Question

Помогите мне срочно пж

Answer 1

$(y^{-2}-x^2)(x^{-1}-y^{-1})=( \frac{1}{y^2}-x^2) (\frac{1}{x} -\frac{1}{y} )=\\\\=\frac{1-x^2y^2}{y^2} \cdot \frac{y-x}{xy} = \frac{(1-xy)(1+xy)(y-x)}{y^3\cdot x} \\\\\\(y^{-2}-x^{-2})(x^{-1}-x^{-1})=( \frac{1}{y^2} -\frac{1}{x^2})( \frac{1}{x}-\frac{1}{y})=\\\\= \frac{x^2-y^2}{x^2y^2} \cdot \frac{y-x}{xy} = \frac{(x-y)(x+y)(y-x)}{x^3y^3} = \frac{-(x-y)^2(x+y)}{x^3y^3}$